Why should I boil pretzels in baking soda water before baking?

Question

This weekend I made pretzels from Alton Brown's recipe.

This recipe, and others I've seen, call for dipping the pretzels one by one in boiling water with baking soda for 30 to 60 seconds.

I assume the boiling water will help the pretzels come up to temperature more quickly so they cook thoroughly, is this correct?

What benefit does the baking soda bring - is it important in forming a crust? If so, why?

Answer 1

The pretzel originates in Germany, where it is called Laugenbrezel. It was originally prepared in a alkali solution, which is where the "Laugen" part of the word comes from; typically, lye was used, but baking soda gets you most of the way there without a trip to the pharmacy (a Mexican or Asian market may do the trick if you want culinary lye).

The alkali solution is what causes the crust to brown so deeply, and it's most of the difference between a pretzel and a bagel. A bagel would typically be boiled in a malted sugar solution instead. The flavor is also affected, but I don't know how to describe the difference; there's a very pronounced aroma difference if you skip this step. To me, you end up with nothing more than a pretty breadstick unless the dough gets that alkali bath.

If you do use culinary lye, use gloves and don't rush anything. I think you may find it safer to boil the pretzels then dip in a cold culinary lye solution sensibly placed in a container in your kitchen sink.

In Germany, the pretzel shape isn't the only option for Laugen. Little rolls calls Laugenbrötchen and longer, roughly baguette-width sticks called Laugenstangen are also popular. On my most recent trip last year, the Laugenstangen were frequently sold in the form of sandwiches, though I don't remember seeing many of those when I was first living there in the mid-90s.

Answer 2

It's there to increase the pH (make it more basic), which gelatinizes the crust. This in turn leads to a brown one, desirable in pretzels. If you hunt up the transcript for the episode ("Pretzel Logic", which can be found here: link, Scene 8) Alton goes into some detail about why this is, and why commercial makers get a browner crust than home bakers generally get. In short, they use more hazardous ingredients in the water.